SLAM!!
CRACK!
'As expected... Wounds Rider inflicts heal very slowly.'
'In contrast, Lancer's attacks heal almost instantly.'
'The difference is...'
Watching the two's continued skirmish, Koga vaguely grasped the issue.
'Verifying this is simple...'
"Lancer! Use your Noble Phantasm!"
Deliberately using a Command Spell to restore his mana, Koga spoke firmly.
"Understood!"
The magic spear was gripped with both hands. Crimson flames erupted from its tip. Cu Chulainn didn't ask why—he simply acted.
Rikuo immediately retreated to avoid being caught in the crossfire.
He'd personally experienced Cu Chulainn's Noble Phantasm—there was absolutely no safe way to receive it.
"Hmph, a last desperate struggle."
The surging mana was naturally detected by the Shikon no Tama.
Unlike the youkai's use of youkai power, Servants almost exclusively used energy called magical power.
And Masters could convert their own power into the magical power Servants required.
Spiritual power, youkai power—all were included.
Except for the Great Dog Demon, Rikuo, and the Shikon no Tama who possessed inherent youkai power, all other Servants used magical power.
"[Gae Bolg]—Soaring Spear that Strikes with Death!"
Leaping to low altitude, Cu Chulainn hurled the mana-filled spear forward with one hand.
WHOOSH!!
With no intention of dodging, the Shikon no Tama took the hit head-on.
BOOM!!
CRASH!!
The explosion erupted, violent shockwaves sweeping across the land in all directions.
Debris and dirt splattered outward.
A massive hemispherical dome could be seen forming on the ground.
That was the trace and range of mana dissipation and destruction...
Cu Chulainn's Noble Phantasm was precisely this devastatingly powerful technique.
Crack...
The body was rapidly regenerating. Yet from within the thick smoke, the Shikon no Tama sensed those three presences gradually fading away.
"Trying to escape?"
Bending its upper body, it prepared to pursue.
'Wait... You need to intercept the Great Dog Demon personally.'
But Naraku's voice made it somewhat displeased.
'If Muzan dies, it will all be for nothing.'
Yet that stated fact forced it to abandon thoughts of pursuit.
"Fine. The Great Dog Demon can probably kill me two or three more times anyway."
"After I transform again, I'll be able to handle Rider and Lancer easily."
Regarding its own life and death, the Shikon no Tama was quite indifferent. After all, each resurrection would only make it stronger until no one in this war could defeat it.
Victory was merely a matter of time...
Neither the Great Dog Demon nor Kirinmaru held any fear for it.
"By the time I intercept the Great Dog Demon, everything should be wrapping up. Kagome has also brought back the last shard..."
Thinking of the plan with Naraku, it then headed in a different direction.
...
"It's not pursuing?"
Koga stopped running and glanced back at the rear where there was no sign of pursuit.
After Cu Chulainn released his Noble Phantasm, he'd immediately informed the other two to retreat.
He'd expected a chase, but it seemed the Shikon no Tama had no intention of continuing the fight.
"Tch, just like you said—that monster took my full Noble Phantasm and it meant nothing."
Cu Chulainn could sense the opponent was still alive and couldn't help but find it troublesome.
"Berserker is harder to deal with than I imagined."
Not expecting this youkai called Nurarihyon to be so difficult, Rikuo subconsciously compared it to his grandfather.
'Even with all the Hundred Demons attacking, I could only damage it without killing it.'
'I don't know why Nenekirimaru barely affects it either.'
Previously he'd deployed his Reality Marble for a group beatdown, but the result was he had no chance of winning.
Even if the Shikon no Tama stood still and let him attack until he ran out of youkai power, there would be no real damage.
If Koga and Cu Chulainn hadn't arrived, he might truly have struggled against this Servant.
"That guy probably has some special ability."
"I was observing just now—wounds from Rider's sneak attacks heal very slowly."
"But wounds from Lancer's direct combat heal almost instantly."
"This was quite obvious when you two attacked together earlier."
Koga then slowly revealed the secret he'd observed.
"Could it be due to Nenekirimaru?"
"I thought so too at first, that your sword was special—but that wasn't it."
"When Lancer first attacked it with flames, those burns also healed slowly."
Facing Rikuo's question, Koga shook his head.
"But the second time I used flames, it regenerated instantly."
"That might be because it noticed you by then."
"Hm?"
"This is just my theory—I don't know if it's true."
"That guy might have extremely high regeneration against attacks it perceives."
"But against attacks from blind spots, the healing is somewhat delayed."
"It's not that it can't be killed—it just requires the right method and technique."
Hearing Koga's description, Rikuo and Cu Chulainn began recalling everything from the battle.
"So... fighting it head-on is essentially unwinnable?"
"You saw it yourself—even taking a Noble Phantasm blast of that magnitude, its presence was completely unaffected."
"Tch..."
Hearing this, Cu Chulainn understood that was probably a Servant's inherent skill.
Just like his [Protection from Arrows], Berserker also possessed abilities like regeneration and defense.
Without finding the correct approach, it might truly be unkillable.
"Striking from a blind spot with a lethal attack..."
"Only then might it be possible to defeat..."
Murmuring softly, Rikuo also thought of his grandfather, his father, and himself.
In a sense, Nurarihyon was indeed a youkai very difficult to defeat head-on.
His father, Nura Rihan—known as the strongest Second Generation of the Nura Clan—had been killed by a single calculated blade.
Because the enemy couldn't figure out how to beat his father head-on, they'd orchestrated that incident.
"You head back and pass this message to Kagome. Cu Chulainn and I will keep following that thing."
"No matter what, that thing will eventually meet up with Naraku."
Koga looked at the contemplating Rikuo and spoke.
"Don't worry about us. We can't kill that thing, but retreating won't be a problem."
"Either way, we have no intention of handing the Dragon Balls over to Naraku and the Shikon no Tama."
"Indeed—even giving them to this guy's Master, that pretty lady, would be fine by me. But giving them to those two disgusting enemies? Forget it."
Hearing the master and servant speak like this, Rikuo didn't refuse. He reverted to his human form and replied earnestly.
"Then please, both of you—stay safe."
"Heh."
"Likewise."